Work piece holder for a grinding machine



1965 P. M. BULTINCK WORK PIECE HOLDER FOR A GRINDING MACHINE Filed Nev. 15, 1962 3 Sheets-Sheet l FIG.2

FIG. 7

IN VEN TOR.

w% N Y II E T TN L R U Q B T T M A M? Mm 1965 P. M. BULTINCK 3,199,253

WORK PIECE HOLDER FOR A GRINDING MACHINE Filed Nov. 15, 1962 3 Sheets-Sheet 2 lill l FIG. 4

INVENTOR,

PAUL M. BULT l N CK ATTORNEYS Aug. 10, 1965 P. M. BULTINCK WORK PIECE HOLDER FOR A GRINDING MACHINE 5 Sheets-Sheet 3 Filed Nov. 15, 1962 FIG. 6

INVENTOR.

PAUL M. BULTINCK ATTORNEYS United States Patent 3,35 ,253 ll $32K EQLEER A GRWDL'NG MAQHHNE M. Eultinch, 2726 55. 3rd $12, Niles, Mich.

Filed Nov. .15, 1%2, her. No. Z37,%6il 4 Claims. (Ql. 51-437) The present invention relates to a grinding machine and more particularly to a work piece holder for a surface grinding machine.

in the operation of machine shops and small tool departrnents, occasional surface grinding operations are required on small parts and pieces of special design and shape with cylindrical features, and the number of these operations performed in the shop or department is not sumciently large to warrant investment in the relatively large machines normally employed in this type of operation, or the time, and hence the expense, required to set up the larger conventional machines for performing the operation can not be assumed in the final price of the finished part or piece. While some of the grinding operations are of such a size and nature that they can be performed with hand tools, the labor costs usually render the hand procedure prohibitive. It is therefore one of the principal objects of the present invention to provide a power operated surface grinding machine which can be easily and readily mounted on conventional or standard grinding machines and operated efiiciently to perform the grinding operation, and which can be readily adapted to perform a variety of different operations on a wide variety of parts and pieces of different sizes and shapes.

Another object of the invention is to provide a relatively small, easily handled, moved and carried grinding machine for small parts and pieces, which is so designed and constructed as to give maximum speed and accuracy in the grinding operation, and which is adapted to be placed in various positions and secured in place on a work support table or plate without the use of any special or complicated fixtures, or other types of mounting and securing means.

Still another object of the invention is to provide a compact, simple and rugged surface grinding machine for small parts and pieces in which the parts or pieces are rorated on fixed non-rotatable dead centers and in which the part or piece can be easily and accurately adjusted using only one or two adjustment means for inserting, adjusting and removing the part or piece.

A further object is to provide a small power grinding machine which is so constructed and designed that it can be fabricated using standard equipment, tools and dies and which, while requiring little service attention to maintain it in optimum operating condition, can be serviced and repaired without any special tools or skills.

Additional objects and advantages of the present invention will become apparent from the following description and accompanying drawings, wherein:

FIGURE 1 is a perspective view of the present grinding machine;

FIGURE 2 is an end view of the grinding machine shown in FIGURE 1;

FIGURE 3 is a top plan view of the present grinding machine;

FIGURE 4 is a side elevational View of the grinding machine shown in the preceding figures;

FEGURE 5 is a cross sectional view of the grinding machine, the section being taken on line 55 of FIG- URE 3;

PEG RE 6 is a vertical cross sectional view of the 5. 3 Patented.

FIGURES 7 and 8 are fragmentary vertical cross sectional views, the sections being taken on lines 7-] and td, respectively, of FlGURE 3.

Referring more specifically to the drawings, numeral 1t) designates generally the present grinding machine, numeral 12 a bed having thereon a head stock member 14 and tail stock member 16, the head and tail stock members being joined at each end of base member 13, and the t ree members preferably being formed as a single metal casting. The base is machined on side 2% and bot tom 22 to provide accurate surfaces for supporting the bed on a standard grinding machine table and to provide straight surfaces on one side and bottom of the bed for accurately and firmly clamping the bed in a fixture on the standard grinding machine.

Mounted on head stock member lid is a rotatable head plate 24 journalled on a stem 26, one end of which is seated in a bore 28 in head member 14 and the other end of which is provided with a ball bearing secured thereto and seated in and secured to the hub of plate 24. It is seen that plate will rotate freely on stem 26 while the stem is held rigidly and non-rotatably in head member is by a set screw 34 threadedly received in a hole in head member lid.

The tail stock member 15 is provided with a bore 443 in axial alignment with bore of head stock member 14 and contains a longitudinally slidable stem d2 held firmly in place, after a longitudinal adjustment of the pin has been made, by the clamping action afforded by the portion of member to above slot 41 being deflected downwardly by screw The screw extends through a lug 4-6 and is threadedly received in lug d8. Rotation of the screw to tighten it causes the head portion to deflect downwardly into slot ll and thereby clamp stem 42 firmly in its adjusted position in tail stock member 16.

Sue of the primary advantages of the present grinding machine over other machines commercially available is the head and tail stock dead centers provided by stems and These two stems are non-rotatable and, once an adjustment has been made, the work piece placed between the two dead centers is held firmly in place by the tightening of screw in order to rotate the work piece, the drive plate is provided with a key slot and a dog (not shown), clamped at one end to the work piece and seated at the other end in the key slot. Thus, it is seen that the work piece to be ground is held firmly by the two dead center tail stock stems and is rotated independently of the two dead centers by the rotation of face plate 2d and the dog attached thereto.

The head plate is driven by a motor as adjustably mounted on bed 12 by a bracket as, the bracket being pivoted to the lower portion of head stock member 34 by an extension as of the bracket and a screw as extending through the extension and being threadedly received in a hole in the head stock member. The bracket is secured to the motor by a pluraiity of screws 6% extending through bosses 7 3 on the inner face of motor as. A gear reduction unit 71 is built into the motor housing and has a power output shaft (not shown) extending outwardly through boss '72 and through bracket 62. Mounted on the output shaft of the gear reduction shaft is a drive wheel 73 having a hub '74 for receiving the output shaft and containing a set screw for retaining the Wheel on the shaft in proper driving relation with face plate 24. The periphery of drive wheel 73 is provided with an annular groove 76 in which is disposed an annular rubber drive iernber 78 which engages the periphery of hub 79 of plate 24 and thereby drives the plate which in turn, through the dog previously described, drives the work piece. The frictional engagement of rubber drive member 73 can e adjusted to give the proper driving relationship between the member and the periphery of hub 79 by loosening winged nut 88 secured to the upper end of head stock member 14 and extending through a slot 82 in bracket 62, and while the nut is loosened, tilting the bracket either to the right or left, as viewed in FIGURE 2, to provide the required pressure of rubber member 78 on the head plate hub. After an adjustment has been made, the nut is again tightened on the bolt, thereby retaining the bracket, motor and wheel '73 in their adjusted position.

In the operation of the present surface grinding machine, a work piece having a cylindrical portion to be ground is placed between the two dead centers provided by stems 26 and 42. Stem 42 is moved endwise to seat the center thereof in a hole suitably provided in the work piece, and screw 44 is then tightened to hold the work piece firmly but rotatably between thetwo stems. A dog placed upon the work piece and extending into key slot 58 forms a driving relationship between plate 24 and the work piece. When the work piece has been properly mounted in the grinding machine, the machine is then placed on a standard grinding machine preparatory to the actual grinding operation, the bed 12 being clamped or otherwise supported in the standard grinding machine for the operation. When the grinding operation is performed, motor 68 is started, thus rotating wheel 73 and plate 24 and, through the dog, the work piece, between the twodead centers provided by stems 26 and 42, the grinding wheel on the standard grinding machine performing the actual grinding'operation. The present grinding machine readily permits relatively small pieces to be easily handled and the working operation readily and accurately performed without any complicated or inconvenient adjustment procedures, and the work piece can be easily measured from time to time as the grinding operation proceeds, in order to determine whether the proper dimensions are being obtained, Without removing the work piece from the machine.

While only one embodiment of the present invention has been described in detail herein, various changes and modifications may be made therein without departing from the scope of the invention.

I claim:

1. A work piece holder for a surface grinding machine, comprising a bed having an elongated base with straight parallel sides and a flat straight bottom, a head stock member at one end of said base with a hole therethrough parallel with said base, a tail stock member at the other end of said base with a hole therethrough in axial alignment with the hole in said head stock member and a slot extending from one side to said hole, stems disposed in each of said holes and having facing conically shaped points forming dead centers for work pieces mounted therebetween, a screw for partially closing said slot for gripping the stem in the hole in the tail stock member in an adjusted position, a means for retaining the stem in said head stock member rigidly in fixed position in said member, a face plate with a T-groove across the face thereof rotatably mounted on the stem of the head stock member, said face plate member having a rearwardly extending hub portion between said plate and head stock member, a motor including a gear reducer with an output shaft, a drive wheel mounted on said shaft and having an annular rubber member on the periphery for engaging said hub portion, and a bracket pivotally mounted on said head stock member and supporting said motor.

2. A work piece holder for a surface grinding machine, comprising a bed having a head stock member at one end of said base with a hole therethrough parallelwith said base and a tail stock member at the other end of 4 said base with a hole therethrough in axiai alignment with the hole in said head stock member and a slot extending from one side to said hole, stems disposed in each of said holes and having facing conically-shaped points forming dead centers for work pieces mounted therebetween, a screw for partially closing said slot for gripping the stem in the hole in the tail stock member in an adjusted position, a means for retaining the stem in said head stock' member rigidly in a fixed position in said member, a face plate rotatably mounted on the stem of the head stock member, said face plate member having a rearwardly extending hub portion between said plate and head stock member, a motor including a gear reducer with an output shaft, a drive wheel mounted on said shaft and engaging said hub portion, and a bracket piv otally mounted on said head stock member and support ing said motor.

3. A work piece holder for a surface grinding machine, comprising a bed, a head stock member at one end of said base with a hole therein parallel with said base and a tail stock member at the other end of said base with a hole therein in axial alignment with the hole in said head stock member, stems disposed in each of said holes and having facing comically-shaped points forming dead centers for work pieces mounted therebetween, a means for retaining the stem in said tail stock member in an adjusted position, a means for retaining the stem in said head stock member rigidly in fixed position in said member, a face plate rotatably mounted on the stem of the head stock member, a hub-like portion on said plate disposed between said plate and head stock member a motor with an output shaft, a drive wheel connected to said shaft, drive means interconnecting said wheel and face plate, and a bracket pivotally mounted on said head stock member and supporting said motor.

4. In a work piece holder for a surface grinding machine: a bed having an elongated base with straight parallel sides, a head stock member at one end of said base and a tail stock member at the other end of said base, axially aligned stems supported by said members and having facing conically-shaped points forming dead centers for work pieces mounted therebetween, a means for re taining the stern in said tail stock member in an adjusted position, a face plate rotatably mounted on the stem of the head stock member, said face plate member havinga rearwardly extending hub portion between said plate and head stock member, a motor including a gear reducer with an output shaft, a power means having an output shaft, a drivewheel mounted on said shaft and having an annular rubber member on the periphery for engaging said hub portion, and a bracket pivotally mounted on said head stock member and supporting said motor.

References Cited by the Examiner UNITED STATES PATENTS 53,994 4/65 Lissenbee 51237 237,487 2/81 Conklin 51237 I 433,218 7/90 Salick 51237 1,203,149 10/16 Smith 82-2 1,240,474 9/17 Moore et al. 822 1,723,356 8/29 Knowles 8245 2,444,559 7/48 Fay 51-236 2,746,218 5/56 Bowie et a1 51-237 2,834,163 4/58 Fay 51-237 2,842,905 7/58 Rolirr 5l236 J. SPENCER OVERHOLSER, Primary Examiner.

FRANK E. BAILEY, FRANK H. BRONAUGH,

- I 1 Examiners. 

3. A WORK PIECE HOLDER FOR A SURFACE GRINDING MACHINE, COMPRISING A BED, A HEAD STOCK MEMBER AT ONE END OF SAID BASE WITH A HOLE THEREIN PARALLEL WITH SAID BASE AND A TAIL STOCK MEMBER AT THE OTHER END OF SAID BASE WITH A HOLE THEREIN IN AXIAL ALIGNMENT WITH THE HOLE IN SAID HEAD STOCK MEMBER, STEMS DISPOSED IN EACH OF SAID HOLES AND HAVING FACING CONICALLY-SHAPED POINTS FORMAING DEAD CENTERS FOR WORK PIECES MOUNTED THEREBETWEEN, A MEANS FOR RETAINING THE STEM IN SAID TAIL STOCK MEMBER IN AN ADJUSTED POSITION, A MEANS FORO RETAINING THE STEM IN SAID HEAD STOCK MEMBER RIGIDLY IN FIXED POSITION IN SAID MEMBER, A FACE PLATE ROTATABLY MOUNTED ON THE STEM OF THE HEAD STOCK MEMBER, A HUB-LIKE PORTION ON SAID PLATE DISPOSED BETWEEN SAID PLATE AND HEAD STOCK MEMBER, A MOTOR WITH AN OUTPUT SHAFT, A DRIVE WHEEL CONNECTED TO SAID SHAFT, DRIVE MEANS INTERCONNECTING SAID WHEEL AND FACE PLATE, AND A BRACKET PIVOTALLY MOUNTED ON SAID HEAD STOCK MEMBER AND SUPPORTING SAID MOTOR. 